Number of years since founding, private or public -- none of these things play much of a role in designating status. It's about attitude, mentality and culture.

You pretty much have to succumb to some regular corporate structure -- relatively stodgy human resources and payroll departments for example -- but, where the magic happens -- in programming, products, services, development, content, whatever you do -- there's no reason to ever lose the fire.

In my admittedly narrow view, the best companies remain in start-up mode forever. But this doesn't prohibit them from being profitable. Losing money is certainly not a prerequisite for start-up status.

It's almost certain to happen early, often and quite possibly as you mature and hit growth spurts and growing pains. It's all about how you manage the process.

Because a great management team runs an equally as awesome business, Amazon will never need to find a buyer. Not like Zipcar (ZIP) . By all accounts, Zipcar had no choice but to sell out . That makes cries that you'll never patronize them again well-intentioned, but just as asinine as vowing to stop listening to Greenday because they traded Bay Area clubs for international arenas and stadiums.

Hating on big corporations like Sarah Lacy did over at PandoDaily is not even so 2012 . It's very 1990 let's go protest the Gulf War in front of the Chevron Building .

So Zip went down. And, to a certain extent, that does suck. But who cares who signs the checks? Zipcar will be Zipcar. Just like my favorite bank -- ING Direct -- will remain better than the alternative even after getting taken out by Capital One (COF) .

It's cold hard reality. Some companies will just never be able to persist on their own. If you want the concept of car sharing to exist, at least as Zipcar organized it, you better hope a company with cash steps up.

When you approach the notion of start-ups and M&A using my lens, Netflix (NFLX) becomes the next one to fall. Carl Icahn knows this, which is one reason why he decided to give Reed Hastings a little hell . Hastings responded, not surprisingly, by making it more difficult for Icahn to make a move; however, the Netflix CEO did this at what could be his shareholders' expense .

That's the kicker here. Companies such as Netflix and Zynga (ZNGA) make perfect candidates to go the way of Zipcar, but their CEOs have enough control -- officially or not -- to block an unfriendly party from getting too hostile. While it does not and probably never will require a bailout, Facebook (FB) , controlled by Mark Zuckerberg, operates under the same structure.